John got himself a brand new Jaguar XJS V12 and he's 'living the dream' except for one nagging detail. The dealer told John that he has to change the air in the tires at regular intervals in order not to void the warranty. Does John need to purchase special OEM Jaguar air? Can he do the job himself? Is the Jaguar dealer pulling John's leg? How hard? Answers to these questions and more on this episode of the Best of Car Talk.